package com.sky.aspect;

import com.sky.annotatio.AutoFill;
import com.sky.constant.AutoFillConstant;
import com.sky.context.BaseContext;
import com.sky.enumeration.OperationType;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.time.LocalDateTime;

/**
 * 自定义切面,实现公共字段填充
 */
@Aspect
@Component
public class AutoFillAspect {

    /**
     * 切入点
     */
    @Pointcut("execution(* com.sky.mapper.*.*(..)) &&@annotation(com.sky.annotatio.AutoFill)")
    public void AutoFillPointCut(){}

    /**
     * 前置通知,为公共字段赋值
     * @param joinPoint
     */
    @Before("AutoFillPointCut()")
    public void autoFill(JoinPoint joinPoint) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {

        //获取当前被拦截方法的数据库操作类型
        //反射！
        MethodSignature signature = (MethodSignature)joinPoint.getSignature();//方法签名对象
        AutoFill autoFill =signature.getMethod().getAnnotation(AutoFill.class);//获得方法上的注解对象
        OperationType operationType = autoFill.value();//获得数据库操作类型

        //获得当前被拦截放的参数-实体对象
        Object[] args = joinPoint.getArgs();
        if(args==null||args.length==0){
            return;
        }
        Object entity = args[0];

        //准备赋值的数据
        LocalDateTime now = LocalDateTime.now();
        Long currentId= BaseContext.getCurrentId();

        //根据当前不同的操作类型，为对应的属性通过反射赋值
        if(operationType==OperationType.INSERT){
            //四个字段
            Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME, LocalDateTime.class);
            Method setCreateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER, Long.class);
            Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
            Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);

            //通过反射为对象属性赋值
            setCreateTime.invoke(entity,now);
            setCreateUser.invoke(entity,currentId);
            setUpdateTime.invoke(entity,now);
            setUpdateUser.invoke(entity,currentId);
        }
        else if(operationType==OperationType.UPDATE){
            //两个字段
            Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
            Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);

            setUpdateTime.invoke(entity,now);
            setUpdateUser.invoke(entity,currentId);
        }
    }
}
